Great Britain's Colin Fleming is out of the US Open men's doubles after he and partner Treat Huey lost to Leonardo Mayer and Joao Sousa in the third round.
Fleming and Huey had beaten Lleyton Hewitt and Sam Groth in the second round, but lost the opening set to Mayer and Sousa 6-4 on Court Five.
The Briton, who could feature in the Davis Cup semi-final against Australia later this month, and his partner produced their only break of serve in the second set, to take it 6-3 and force a decider.
However, Mayer and Sousa caused problems on their opponents' serve throughout the match, bringing up 11 break points and their pressure finally told as they won the final set 6-4 to progress.
There was better news for another Briton in men's draw, with Dominic Inglot reaching the last eight, alongside partner Robert Lindstedt.